There are two reasons that the data you retrieve does not correspond to country statistics offices:
Firstly, the trade data collected by our econometricians is harmonised and aggregated using a variety of data sources of which country statistics offices are only one. This means that the data will not be identical to those coming from any other source but the trends and patterns will be similar.
Secondly, DeltaMetrics uses the HS 1996 coding system for sectors. This differs to the SITC system that some country statistics offices use but is consistent with United Nations Comtrade practices.